Numerous frequency modulated crystal oscillator circuits have been advanced in connection with providing an output frequency that is a linear function of an inputted modulation signal or voltage. In many such circuits a voltage variable capacitor or tuning diode is utilized. However, as is well known, the tuning diode is not linear over a wide range of modulation voltages. That is, the capacitance of the tuning diode does not vary linearly with the inputted voltage over a relatively wide range of voltages. To compensate for such non-linearity and thereby achieve a linear relationship over a desired range of output frequencies, circuits have been devised directed to altering the reactance of the crystal. Briefly, the non-linearity of the tuning diode is compensated for by a change in reactance of the crystal using frequency dependent passive electrical elements in series and/or in parallel with the crystal. In another type of crystal oscillator, instead of changing the reactance of the crystal to compensate for non-linearity, the oscillator includes a configuration of circuit elements wherein the series resonant frequency of the crystal changes in response to a phase change caused by the modulation signal. Regardless of the type of circuit used to maintain linearity, such known frequency modulated crystal-controlled oscillators are complex in design, include a relatively great number of electrical components in order to achieve the desired linearization, and are relatively expensive to manufacture because of the number of components required.